Aceraceae

Trees or shrubs, buds with many perules. Leaves decussate, petiolate, entire, palmate or pinnate, appearing simultaneously with the flowers or later, exstipulate. Inflorescence racemose, corymbose or spicate, terminal with 2-4 leaves, or rarely terminal or axillary without leaves. Monoecious or dioecious, flowers actinomorphic, ♂ and ♀, ovary in the ♂ fls more reduced than stamens in ♀ fls. Calyx and corolla 4-5-merous. Stamens 4-10, mostly 8, hypogynous or perigynous. Disc extraor intrastaminal. Ovary superior, 2-celled, laterally flattened, each cell with 2 ovules. Fruit a samara, splitting into 2, rarely 3, winged usually 1-seeded parts. Seed without endosperm, radicle elongate, cotyledons foliaceous, or thickened, plicate, involute or flat. Distr. Ca 200 spp. in the N. hemisphere, only in Malaysia crossing the equator.